1. Field of the Invention
This invention is in the field of slurry fuels of liquid fuel particles, suspended in liquid water, for use in engines and burners.
2. Description of the Prior Art
Many kinds of liquid fuels are presently burned efficiently in diesel engines, particularly, but not exclusively, petroleum derived fuels. These petroleum derived fuels vary widely in viscosity, and hence in ease with which the liquid fuel, injected into the engine cylinder prior to combustion, can be atomized into the very small droplets needed for efficient combustion. As fuel viscosity increases, higher fuel injection pressures are needed for adequate atomization, and the fuel spray path length needed also increases. As a result, high viscosity fuels, such as petroleum residual fuels, can only be burned efficiently in diesel engines of large piston diameter, of the order of two to three feet. When such residual fuels are used in medium and small bore engines, either fuel atomization is inadequate, or the liquid fuel is sprayed onto the cylinder wall, and inefficient combustion results.
A method for efficiently burning these high viscosity, and low cost, fuels in medium and small bore diesel engines would be very useful.
3. Definitions
Those liquid fuels which are largely, or essentially completely, insoluble in water, are suitable for the purposes of this invention. Preferably the vapor pressure of these liquid fuels is very low at the temperature of boiling water at one atmosphere ambient pressure. Most such fuels in common use are derived from crude petroleum, as for example, residual fractions left after refined portions, such as gasoline, diesel fuel, and lubricating oil fractions have been removed from the crude oil. Some high viscosity, low vapor pressure, liquid fuels can be derived from non-petroleum sources, such as vegetable oils, coal tar derivatives, wood tar derivatives, etc.
The term water is used herein and in the claims to mean a chemical comprising, principally, molecules containing two atoms of hydrogen and one atom of oxygen, i.e., H2O. The term liquid water is used herein and in the claims to mean water in the liquid state. The term steam is used herein and in the claims to mean water in the vapor state. The term wet steam is used herein and in the claims to mean a mixture of steam and liquid water.
The term slurry fuel is used herein and in the claims to mean a mechanical mixture of a liquid fuel in liquid water, wherein the fuel is largely insoluble in water.
The term wet steam is used herein and in the claims to mean a mechanical mixture of water vapor and liquid water at essentially the same temperature.
The term trajectory is used herein and in the claims to mean the line, either straight or curved, that a moving mass describes in space.
A steam fuel slurrifier of this invention comprises a liquid fuel nozzle and a wet steam nozzle, which create a liquid fuel jet and a counterflowing steam jet. The steam jet intersects the fuel jet and atomizes the liquid fuel into many small droplets within an atomization chamber. Heat transferred from the steam to the fuel causes steam condensation on the fuel droplet surface, which becomes coated with liquid water. This mixture of liquid fuel and steam moves out of the atomization chamber into a surrounding and rotating mixer chamber, into which additional mixer water is added, to create a liquid fuel in liquid water slurry, wherein liquid water is the continuous phase. Centrifugal force caused by rotation of this slurry within the mixer chamber, keeps the slurry outside of the atomization chamber where it would interfere with atomization. The resulting slurry of small liquid fuel droplets suspended in a continuous liquid water phase can be removed from the mixer chamber and used subsequently as a slurry fuel in conventional diesel engines. By thusly preatomizing the liquid fuel outside of the diesel engine, high viscosity fuel such as petroleum residual fuels can be efficiently burned in medium and small bore engines. These engines cannot otherwise efficiently use such high viscosity fuels due to inadequate fuel spray path length for the needed fine atomization. This is a principal beneficial object of this invention that low cost residual fuels can be efficiently utilized in medium and small bore diesel engines, by thusly preatomizing these high viscosity fuels outside the engine.
A schematic, cross sectional view of an example form of a steam fuel slurrifier apparatus of this invention is shown in FIG. 1.
Another form of steam fuel slurrifier apparatus of this invention is shown partially and in cross section in FIG. 2.
A schematic diagram of the process steps of a steam fuel slurrifier is shown in FIG. 3.
A schematic, cross sectional view of a fuel or steam nozzle for creating a hollow cone-shaped jet is shown in FIG. 4.
Two views of a multi-hole fuel or steam nozzle, with valves, is shown in FIG. 5A and FIG. 5B.